If the goal is realism then somethings wrong. The goal should be entertainment. Most of my meals are mundane and boring. Going out to diner with friends in a fine restruant is an entirely differant story. If you can simulate that then you add something to the game. You arrive at the next town, head to the tavern, have a meal, some drinks, individuals head out to sell loot and restock, you spend the night at the inn and you head out. You don't do it because you have to, but because it is going to take people time to do everything they need to and in the real world they need to use the bathroom, grab something to eat or get a fresh drink. Setting in the tavern telling tall tales is a way to pass the time while you wait. Spending the night in an inn is a way to let people know you are afk and when you are back.

There is certainly no problem with making food a resource in the game that needs to be managed. You eat food, you drink a potion, what differance does it make. It doesn't matter if you died in some fight because you ran out of healing potions or because you haven't eaten or slept in days. It's a resource to be managed, you failed to manage it and as a result you died. Forget roleplaying though. That isn't roleplaying, but rather it's playing a game according to the rules of the game. The player doesn't want to watch a movie of their character walking through the world killing everything it comes across. They want an active role. They want decisions that at least give the appearance of mattering. So they need resources to manage. Skill/attribute points, potions, food, gold, backpack space, etc. You don't want to just give them widgets, every five minutes a widget disappears, when they run out of widgets they die so they have to keep hunting widgets. If that's what you want to make food then don't bother.

When it comes to roleplaying though don't mistake props for resources to be managed. Resources management is part of the game. Props are just for laughs and giggles. The wolves are running rampant over the farms killing cows as soon as they pop so a steak here costs an arm and a leg. You're in a sea port so its fish everything in every tavern you go to. You find a run down tavern in the back woods, stop for a meal and get sick. You drank too many ales in too short a period of time so now you can't walk a straight line, you're insulting the local residents and a detail of the city guard is following you down the street until you leave town. That adds something to the atmosphere which promote roleplaying, but having to collect and eat 1,000 apples, all apples, nothing but apples, until you hope you never see another apple again adds nothing to the roleplaying.

Perhaps some sort of hp regenerator, linked with eating?

The player sets (and can change at any time) the level of eating, from starvation to gormet.

At startavion, you loose x hp 3 times a day (when you should be eating).

At gormet, you gain x hp 3 times a day (because you have eaten)

At mediocre, you neither gain, nor loose any points.

You have a fixed amount of food, which you can buy at shops, find, ect. And when you eat (which is fixed), you loose an amount of food based on what level you are at (at starvation, you sue no food, at gormet you use heaps).

Just an idea...
DENC

I think it all depends on the type of RPG. It would be stupid for an RPG like Diablo to have a food system since the player rarely wanders far from town (or at least in the first one they didn't).

However, in a more traditional, "epic" style RPG where the players might have to make there way across a large continent, I could see a food like system working. This is because the adventuring is the main focus in a game like this, while in Diablo the main focus is about combat.

Great input everyone. The system we are using is based on skills. We did not want to go with only a skill level/number to base total proficiency on. To me it is beyond unrealistic to say a player will always perform at the same level no matter what. Using an energy system of sorts that will vary the effectiveness of skills is what we are shooting for. The food (and possibly rest) are going to tied into that. It takes in to consideration the quality/type of food on energy replenishment while the predetermined effort levels for the activities a player can perform will all have a negative effect on the total energy which is calculated against the skill proficiency.

Again thanks for the inputs everyone.